ByErik Stier, CorrespondentMarch 21, 2011

Yemeni army officers react as they join antigovernment protesters demanding the resignation of Yemeni President Ali Abdullah Saleh, in Sanaa, Yemen, Monday, March 21. Three Yemeni army commanders, including a top general, defected Monday to the opposition calling for an end to President Saleh's rule, as army tanks and armored vehicles deployed in support of thousands protesting in the capital.

Sanaa, Yemen — Several of Yemen’s top military commanders – including President Ali Abdullah Saleh's half-brother – defected today, pledging to protect opposition demonstrators after unprecedented violence in Sanaa on Friday.

The defections, which follow the resignations of eight ambassadors over the weekend, remove a critical base of support for the 32-year leader. (Editor's note: The original version overstated how many people resigned this weekend.)

While protesters in Sanaa were jubilant, Yemenis and analysts expressed concern that the developments could foreshadow a military coup or the outbreak of war between the country’s fractured armed forces.

“Saleh’s options have been becoming more limited by the day," says Gregory Johnsen, a Yemen specialist at Princeton University. "Now there are two left – he can try to hang on, which will likely lead to bloodshed, or he can step down.”

For now, at least, Saleh appears determined to stay in power. His defense minister vowed today that the armed forces would remain faithful to Saleh.

“We will not allow under any circumstances an attempt at a coup against democracy and constitutional legitimacy, or violation of the security of the nation and citizens," said the statement, according to Reuters, which obtained a copy.

Ahmar deploys troops to protect protesters

Maj. Gen. Ali Mohsen al-Ahmar, the president's half-brother and longtime ally until today, led the military defections with a televised news conference announcing that he had deployed forces to protect demonstrators.

“Yemen today is suffering from a comprehensive and dangerous crisis, and it is widespread,” said General Ahmar today. “It is because of what I feel about the emotions of officers and leaders in the armed forces, who are an integral part of the people, and protectors of the people, I declare, on their behalf, our peaceful support of the youth revolution and their demands and that we will fulfill our duties."

Several other top commanders, including Gen. Ali Abdullaha Aliewa, adviser of the Yemeni supreme leader of the army, and Brig. Gen. Mohammed Ali Mohsen, head of the eastern division, joined Ahmar, who is head of the first armored division and responsible for the northwestern military zone.

“Major General al-Ahmar's announcement opened the floodgates to military defections,” says Mr. Johnsen, adding that no one wanted to be the last off a sinking ship. “He has been instrumental to keeping Saleh in power and this calculated move has set him up in a position where he and other upper ranks will be able to maintain their positions in a future government.”

Controversy around Ahmar

At today's demonstration in Sanaa, crowds heaved armed and uniformed security forces onto their shoulders in celebration after Ahmar's announcement.

But the major general is a polarizing figure in Yemeni politics. He has been a close Saleh ally for years, leading military campaigns in the north against the Shiite Houthi movement, which have thrown their weight behind Yemen’s uprising.

“There are people in this movement that support the Houthis and do not accept Major General al-Ahmar,” says Salah al-Sharaty, a protester from the nearby province of Mahwuit. “They want to prosecute him for the crimes they feel he has committed during the wars in the north.”

Eight ambassadors, 13 lawmakers resign

The military defections come on the heels of a growing number of political resignations from Saleh’s ruling General People’s Congress Party in the wake of Friday's violence, when gunmen opened fire on thousands of demonstrators from rooftops around the demonstration area, killing at least 45.

In the three days since then, at least three acting ministers – including Huda al-Ban, Minister of Human Rights – resigned from the party in protest of the use of force, which many have attributed to Saleh's regime. At least 13 members of parliament have also resigned from the GPC.

In addition, eight foreign ambassadors, including Abdullah Alsaidi, Yemen's ambassador to the United Nations, have quit their posts in response to the violence.

In what many see as a response to the resignations, Saleh dissolved the cabinet on Sunday. The current government is set to remain in place until Saleh is able to form a new cabinet.

While many see the defections as the beginning of the end for Saleh, some demonstrators fear that the sudden influx of high-profile army members could threaten the outcome of the uprising.

“The timing of this announcement really took us by surprise. We weren’t expecting so much military support so soon,” says student leader Adel al-Surabi. “We need the support to the armed forces, but I’m afraid that this could lead to a military government.”

Saleh’s son, Ahmed, holds the highest military rank in the country as leader of the Republican Guard and Special Forces, while his four nephews head the country’s major military institutions. The possibility of violent conflict between the security forces will largely depend on the loyalty of Yemen’s rank-and-file to Saleh’s relatives, says Johnsen, speaking from Cairo.